Field of the Information
The present invention relates to a composition having a new form of metallic gallium or gallium alloy particles mixed uniformly in a synthetic resin. The present invention also relates to an article of use employing this synthetic resin composition or a fabricated product thereof.
Background Information
There have been known various composite materials in which metals or non-metals are mixed with synthetic resins. Various kinds of metals or non-metals are used as fillers either on their own or as admixtures.
One of the recent marked changes in the construction materials of skis is an increasing shift from wood to plastics in the glide surfacing material and plastic skis to which snow does not stick and which give skiers faster glide. Such material and skis are now available on the market. Active research efforts are thus being made to produce improved glide surfacing materials of skis and several patent applications have been filed in this area. For example, Japanese Patent Public Disclosure No. 58-4573 entitled "Surfacing Material for Skis" shows a surfacing material of ski consisting of a plastic material mixed with a clathrate compound of wax, paraffin or a mixture thereof included in a cyclodextrin. Japanese Patent Public Disclosure No. 62-217980 entitled "Glide Surfacing Material of Ski and Process for Producing the Same" shows a glide surfacing sheet for skis that has granules of a superhigh-molecular weight polyolefinic resin dispersed uniformly in a high-molecular weight polyolefinic resin.
Gallium in the metallic state can be used in solid lubricants and this technique has already been well known as disclosed in U.S. Pat. Nos. 3,391,080 and 3,405,063. However, the melting point of gallium is extremely low (29.78.degree. C.) and special considerations are needed in its processing. Therefore, the use of solid lubricants comprising metallic gallium has been very limited.
Plastic gear materials are also known in the art that have molybdenum disulfide (MoS.sub.2), graphite, etc. incorporated in synthetic resins such as nylons and polypropylene. However, these gear materials are unable to exhibit the intended lubricating property unless molybdenum disulfide or graphite is added in more than several percent. They also have a serious defect in that they are black in color. Hence, it has been desired to make some improvement on those gear materials.
A higher level of water repellency and wear resistance has been desired in plastic compositions and the glide surfacing material of skis. In fact, however, the maximum level that can be attained by the state of the art is no more than those taught in the patents listed above and a need has existed for the accomplishment of further improvements in performance.
The present inventors conducted intensive studies in order to meet this need and found that metallic gallium or gallium alloy could be produced by certain means in the form of fine particles no larger than 150 microns, or even a size of 50 microns and below. When the surfaces of the so obtained gallium or gallium alloy particles (hereunder sometimes simply referred to as "gallium particles" were coated with paraffin or some other material, it became possible to effect uniform dispersion of metallic gallium or gallium alloy in resins which had previously been held impossible to mix with metallic gallium by the prior art. This accomplishment of the manufacture of compositions having the particles of metallic gallium or gallium alloy dispersed uniformly in synthetic resins has led to the development of various articles of use in which the inherent characteristics of the resin compositions are fully exploited.